Dual ratio drive for variable speed hybrid electric supercharger assembly

Abstract

An example engine assembly includes: an electric motor including an electric motor drive shaft; a first clutch positioned to apply torque through a first gear set to an internal combustion engine of the engine assembly; and a second clutch positioned to apply torque through a second gear set to a supercharger of the engine assembly.

What is claimed is: 
     
         1 . An engine assembly, comprising:
 an electric motor including an electric motor drive shaft;   a first clutch positioned to apply torque through a first gear set to an internal combustion engine of the engine assembly; and   a second clutch positioned to apply torque through a second gear set to a supercharger of the engine assembly.   
     
     
         2 . The engine assembly of  claim 1 , wherein the first clutch is configured to engage at a first set of speeds, and the second clutch is configured to engage at a second set of speeds. 
     
     
         3 . The engine assembly of  claim 2 , further comprising a dead zone between the first set of speeds and the second set of speeds. 
     
     
         4 . The engine assembly of  claim 2 , wherein the first clutch is further engaged when a direction of rotation of the electric motor drive shaft changes. 
     
     
         5 . The engine assembly of  claim 1 , wherein the first gear set is optimized to transfer torque. 
     
     
         6 . The engine assembly of  claim 5 , wherein the second gear set is optimized to transfer speed. 
     
     
         7 . The engine assembly of  claim 6 , wherein the first gear set provides a 5:1 drive ratio. 
     
     
         8 . The engine assembly of  claim 7 , wherein the second gear set provides a 2:1 drive ratio. 
     
     
         9 . The engine assembly of  claim 1 , wherein the first gear set provides a higher drive ratio, and the second gear set provides a lower drive ratio. 
     
     
         10 . A dual ratio drive assembly, comprising:
 a first clutch positioned to apply torque through a first gear set from an electric motor to an internal combustion engine; and   a second clutch positioned to apply torque through a second gear set from the electric motor to a supercharger.   
     
     
         11 . The dual ratio drive assembly of  claim 10 , wherein the first clutch is configured to engage at a first set of speeds, and the second clutch is configured to engage at a second set of speeds. 
     
     
         12 . The dual ratio drive assembly of  claim 11 , further comprising a dead zone between the first set of speeds and the second set of speeds. 
     
     
         13 . The dual ratio drive assembly of  claim 11 , wherein the first clutch is further engaged when a direction of rotation of the electric motor changes. 
     
     
         14 . The dual ratio drive assembly of  claim 10 , wherein the first gear set is optimized to transfer torque. 
     
     
         15 . The dual ratio drive assembly of  claim 14 , wherein the second gear set is optimized to transfer speed. 
     
     
         16 . The dual ratio drive assembly of  claim 10 , wherein the first gear set provides a 5:1 drive ratio, and wherein the second gear set provides a 2:1 drive ratio. 
     
     
         17 . The dual ratio drive assembly of  claim 10 , wherein the first gear set provides a higher drive ratio, and the second gear set provides a lower drive ratio. 
     
     
         18 . A method for driving an internal combustion engine and a supercharger, the method comprising:
 engaging a first clutch positioned to apply torque through a first gear set from an electric motor to the internal combustion engine at a first speed of the electric motor; and   engaging a second clutch positioned to apply torque through a second gear set from the electric motor to the supercharger at a second speed of the electric motor.   
     
     
         19 . The method of  claim 18 , wherein the first gear set provides a higher drive ratio, and the second gear set provides a lower drive ratio. 
     
     
         20 . The method of  claim 18 , further comprising:
 reversing a direction of the electric motor; and   reengaging the first clutch to apply torque to the supercharger.